1. Technical Field
The disclosed embodiments relate to a method of measuring a substrate and a method of manufacturing a semiconductor device. For example, the embodiments relate to a method of measuring a thickness of a thin film or a pattern on a substrate.
2. Description of the Related Art
In general, manufacturing processes of a semiconductor device include processes of forming various thin films such as an insulating film, a dielectric film, and a metal film on a substrate formed of a wafer of a monocrystalline silicon material, and processes patterning the various thin films.
Recently, with high integration of semiconductor devices, the number of thin films formed on a substrate has increased, and influences of the physical properties of the thin films on the subsequent processes and on the final device has been further increased.
Thus, after forming the thin film, it is beneficial to evaluate physical characteristics of the thin films and to use the evaluation result for subsequent processes. Various evaluation processes may be executed according to respective physical characteristics of the thin film.
Among the physical properties of the thin film, the thickness of the thin film has a significant influence on the quality of the semiconductor device. For example, when a desired thickness is not achieved in a cell block, it may cause a decrease in the quality of the semiconductor device which may lead to a decrease in yield.
Thus, to measure the uniformity of the thickness of a thin film on a wafer, an apparatus that measures the thickness of the thin film at a plurality of points on the wafer has been disclosed. However, as the semiconductor devices become smaller and smaller, the area to measure a thickness are being further reduced, which may affect the accuracy of the thickness measurement.
As the design rule of semiconductor devices is getting finer, a minute deviation from a target measuring location may cause a measurement error, and this measurement error may lead to an incorrect determination of a thin film thickness on the substrate.